[DLM] Make sock_sem into a mutex

Now that there can be multiple dlm_recv threads running we need to prevent two
recvs running for the same connection - it's unlikely but it can happen and it
causes message corruption.

Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This commit is contained in:
Patrick Caulfield 2007-01-24 11:17:59 +00:00 committed by Steven Whitehouse
parent d043e1900c
commit f1f1c1ccf7

View File

@ -96,7 +96,7 @@ static bool cbuf_empty(struct cbuf *cb)
struct connection {
struct socket *sock; /* NULL if not connected */
uint32_t nodeid; /* So we know who we are in the list */
struct rw_semaphore sock_sem; /* Stop connect races */
struct mutex sock_mutex;
unsigned long flags; /* bit 1,2 = We are on the read/write lists */
#define CF_READ_PENDING 1
#define CF_WRITE_PENDING 2
@ -171,7 +171,7 @@ static struct connection *nodeid2con(int nodeid, gfp_t allocation)
goto finish;
con->nodeid = nodeid;
init_rwsem(&con->sock_sem);
mutex_init(&con->sock_mutex);
INIT_LIST_HEAD(&con->writequeue);
spin_lock_init(&con->writequeue_lock);
INIT_WORK(&con->swork, process_send_sockets);
@ -247,7 +247,7 @@ static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
/* Close a remote connection and tidy up */
static void close_connection(struct connection *con, bool and_other)
{
down_write(&con->sock_sem);
mutex_lock(&con->sock_mutex);
if (con->sock) {
sock_release(con->sock);
@ -262,7 +262,7 @@ static void close_connection(struct connection *con, bool and_other)
con->rx_page = NULL;
}
con->retries = 0;
up_write(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
}
/* Data received from remote end */
@ -276,7 +276,7 @@ static int receive_from_sock(struct connection *con)
int r;
int call_again_soon = 0;
down_read(&con->sock_sem);
mutex_lock(&con->sock_mutex);
if (con->sock == NULL)
goto out;
@ -355,17 +355,17 @@ static int receive_from_sock(struct connection *con)
out:
if (call_again_soon)
goto out_resched;
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
return 0;
out_resched:
if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
queue_work(recv_workqueue, &con->rwork);
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
return -EAGAIN;
out_close:
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) {
close_connection(con, false);
/* Reconnect when there is something to send */
@ -391,7 +391,7 @@ static int accept_from_sock(struct connection *con)
if (result < 0)
return -ENOMEM;
down_read_nested(&con->sock_sem, 0);
mutex_lock_nested(&con->sock_mutex, 0);
result = -ENOTCONN;
if (con->sock == NULL)
@ -417,7 +417,7 @@ static int accept_from_sock(struct connection *con)
if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
printk("dlm: connect from non cluster node\n");
sock_release(newsock);
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
return -1;
}
@ -434,7 +434,7 @@ static int accept_from_sock(struct connection *con)
result = -ENOMEM;
goto accept_err;
}
down_write_nested(&newcon->sock_sem, 1);
mutex_lock_nested(&newcon->sock_mutex, 1);
if (newcon->sock) {
struct connection *othercon = newcon->othercon;
@ -442,13 +442,13 @@ static int accept_from_sock(struct connection *con)
othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
if (!othercon) {
printk("dlm: failed to allocate incoming socket\n");
up_write(&newcon->sock_sem);
mutex_unlock(&newcon->sock_mutex);
result = -ENOMEM;
goto accept_err;
}
othercon->nodeid = nodeid;
othercon->rx_action = receive_from_sock;
init_rwsem(&othercon->sock_sem);
mutex_init(&othercon->sock_mutex);
INIT_WORK(&othercon->swork, process_send_sockets);
INIT_WORK(&othercon->rwork, process_recv_sockets);
set_bit(CF_IS_OTHERCON, &othercon->flags);
@ -466,7 +466,7 @@ static int accept_from_sock(struct connection *con)
addcon = newcon;
}
up_write(&newcon->sock_sem);
mutex_unlock(&newcon->sock_mutex);
/*
* Add it to the active queue in case we got data
@ -475,12 +475,12 @@ static int accept_from_sock(struct connection *con)
*/
if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
queue_work(recv_workqueue, &addcon->rwork);
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
return 0;
accept_err:
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
sock_release(newsock);
if (result != -EAGAIN)
@ -501,7 +501,7 @@ static void connect_to_sock(struct connection *con)
return;
}
down_write(&con->sock_sem);
mutex_lock(&con->sock_mutex);
if (con->retries++ > MAX_CONNECT_RETRIES)
goto out;
@ -553,7 +553,7 @@ out_err:
result = 0;
}
out:
up_write(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
return;
}
@ -757,7 +757,7 @@ static void send_to_sock(struct connection *con)
struct writequeue_entry *e;
int len, offset;
down_read(&con->sock_sem);
mutex_lock(&con->sock_mutex);
if (con->sock == NULL)
goto out_connect;
@ -803,17 +803,17 @@ static void send_to_sock(struct connection *con)
}
spin_unlock(&con->writequeue_lock);
out:
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
return;
send_error:
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
close_connection(con, false);
lowcomms_connect_sock(con);
return;
out_connect:
up_read(&con->sock_sem);
mutex_unlock(&con->sock_mutex);
connect_to_sock(con);
return;
}